Scientific misconduct has garnered recent attention by the media over scandals concerning falsification and fabrication of data surrounding potentially promising breakthroughs in stem-cell research, allegations of plagiarism at a U.S. university, and financial conflicts of interest between researchers and drug companies. While this makes for interesting copy, discussion of scientific fraud provides an excellent opportunity to review ethical standards for research and examine the conflicts that confront researchers today. This review specifically focuses on five areas that involve scientific integrity—plagiarism, falsification, fabrication, authorship, and conflict of interest—as well as nuances in each area that even senior investigators may not be aware of (e.g., self-plagiarism). The standards for ethical conductance of research discussed in this review are those set by many scientific, peer-reviewed journals and by federal and private granting agencies, and therefore it highlights the expectations and guidelines surrounding manuscript and grant submissions and review, and the consequences associated with violations. This review is intended to stimulate discussion among readers and assess what is necessary to become a good, competitive, but ethical researcher, especially in an era of shrinking financial resources for research.

Atherosclerosis is a common disease in pet birds, particularly in psittacines. Little is known about the role of risk factors predisposing birds to this disease. In our study, we tried to detect chlamydiae in formalin-fixed and paraffin-embedded atherosclerotic tissue from 103 pet birds to clarify their role in atherosclerosis. Methods used were polymerase chain reaction (PCR), sequencing, and immunohistochemistry. Histopathologic examination served to classify the extent of atherosclerotic lesions. In the PCR, 4 (3.9%) of 103 cases, all of them with advanced stages of atherosclerosis, were positive. Subsequent sequence analysis revealed high identities (94%–100%) with Chlamydophila psittaci in three cases. Interestingly, two of these birds came from C. psittaci–infected populations. Because of the low incidence (3.9%), the occurrence only in advanced stages, and the association with C. psittaci–infected avian populations, a causal relationship between chlamydiae and atherosclerosis in pet birds is rather improbable.

Different infectious bursal disease virus (IBDV) live vaccines (intermediate, intermediate plus) were compared for their immunosuppressive abilities in specific-pathogen-free (SPF) layer-type chickens or commercial broilers. The Newcastle disease virus (NDV) vaccination model was applied to determine not only IBDV-induced immunosuppression but also bilateral effects between IBDV and NDV. None of the IBDV vaccines abrogated NDV vaccine–induced protection. All NDV-vaccinated SPF layers and broilers were protected against NDV challenge independent of circulating NDV antibody levels. Sustained suppression of NDV antibody development was observed in SPF layers, which had received the intermediate plus IBDV vaccine. We observed a temporary suppression of NDV antibody development in broilers vaccinated with one of the intermediate, as well as the intermediate plus, IBDV vaccines. Different genetic backgrounds, ages, and residual maternal antibodies might have influenced the pathogenesis of IBDV in the different types of chickens. Temporary suppression of NDV antibody response in broilers was only seen if the NDV vaccine was administered before and not, as it was speculated previously, at the time the peak of IBDV-induced bursa lesions was detected. For the first time, we have demonstrated that the NDV vaccine had an interfering effect with the pathogenesis of the intermediate as well as the intermediate plus IBDV vaccine. NDV vaccination enhanced the incidence of IBDV bursa lesions and IBDV antibody development. This observation indicates that this bilateral effect of an IBDV and NDV vaccination should be considered in the field and could have consequences for the performance of broiler flocks.

Xanthohumol (XN), a prenylated chalcone from the hops flower, was examined for its ability to reduce invasion of Madin–Darby bovine kidney (MDBK) cells by Eimeria tenella sporozoites (SZ), as well as to reduce invasion by E. tenella and E. acervulina SZ in the chick host. Additionally, XN was tested as an anticoccidial feed additive at 20 ppm against challenge infections with E. acervulina, E. maxima, and E. tenella. Cell invasion by E. tenella SZ was inhibited 66% by treatment of SZ with 22 ppm XN. This inhibition was associated with an apparent physical disruption of the apical ends of the SZ. Rectal challenges with E. tenella SZ treated with 5, 10, and 20 ppm XN resulted in significantly reduced gross-lesion scores and normal chick-host weight gains compared with challenge with untreated SZ. Oral challenges with similarly treated E. acervulina SZ, accomplished with prior antacid treatment, resulted in significantly reduced gross lesions and reduced oocyst shedding compared with challenge with untreated SZ and were associated with physical disruption of sporozoite morphology. In a pilot test, provision of feed supplemented with 20 ppm XN for 3 days before challenge to 6 days after challenge did not control challenge infections with E. acervulina, E. maxima, or E. tenella as judged by measurements of weight gain, feed conversion, and gross lesions. Although XN-fed chicks infected with E. acervulina and E. maxima shed fewer oocysts than those on control feed, the differences in numbers were not statistically significant (P > 0.05).

An avian adenovirus (AAV) was isolated from liver samples of two 2-wk-old broiler-breeder flocks obtained from grandparents vaccinated at 10 and 17 wks of age with an autogenous inactivated vaccine containing the European AAV 8 (8565 strain) and 11 (1047 strain) serotypes (AAV8/11 vaccine). Affected broiler-breeders exhibited clinical signs and macroscopic and microscopic lesions associated with inclusion body hepatitis (IBH). The isolated adenovirus, identified as Stanford, was molecularly characterized as European serotype 9. The pathogenicity of the Stanford strain was confirmed after inoculation of specific-pathogen-free (SPF) chickens at 1–7 days of age, causing 100% and 20% mortality, respectively. The level of protection against IBH was evaluated in two broiler-breeder progenies from AAV 8/11–vaccinated grandparent flocks and a commercial broiler flock by challenge at 1 or 7 days of age with the AAV 8 and 11 serotypes and/or the Stanford strain. The broiler-breeder progenies and the commercial broiler flock exhibited protection against IBH after challenge. No significant differences in mean body weights were observed at 3 wk of age in any of the evaluated groups. We conclude that broiler-breeder progenies from 30- to 50-wk-old grandparents vaccinated with the AAV 8/11 vaccine were adequately protected against challenge with the AAV 8 and 11 serotypes and the Stanford strain.

The pathogenicity and transmission of a field isolate of reticuloendotheliosis virus (REV) was studied using an experimental model in Japanese quail. Oncogenicity was also evaluated after inoculations in chickens and turkeys. The original REV (designated APC-566) was isolated from Attwater's prairie chickens (Tympanuchus cupido attwateri), an endangered wild avian species of the southern United States. The transmissibility of the REV isolate was studied in young naive Japanese quail in contact with experimentally infected quail. Vertical transmission was not detected by virus isolation and indirect immunofluorescence. Seroconversion was detected in few contact quails, suggesting horizontal transmission. The APC-566 isolate induced tumors beginning at 6 wk of age in quails infected as embryos. Most of the tumors detected in Japanese quail were lymphosarcomas, and 81% of these neoplasias contained CD3 cells by immunoperoxidase. REV APC-566 was also oncogenic in chickens and turkeys infected at 1 day of age, with tumors appearing as early as 58 days after infection in chickens and at 13 wk of age in turkeys. This study was conducted in part as an attempt to understand the potential for pathogenicity and transmission of REV isolated from endangered avian species.

Internal contamination of eggs by Salmonella Enteritidis has been a significant source of human illness for several decades and is the focus of a recently proposed U.S. Food and Drug Administration regulatory plan. Salmonella Heidelberg has also been identified as an egg-transmitted human pathogen. The deposition of Salmonella strains inside eggs is apparently a consequence of reproductive tissue colonization in infected laying hens, but the relationship between colonization of specific regions of the reproductive tract and deposition in different locations within eggs is not well documented. In the present study, groups of laying hens were experimentally infected with large oral doses of Salmonella Heidelberg, Salmonella Enteritidis phage type 13a, or Salmonella Enteritidis phage type 14b. For all of these isolates, the overall frequency of ovarian colonization (34.0%) was significantly higher than the frequency of recovery from either the upper (22.9%) or lower (18.1%) regions of the oviduct. No significant differences were observed between the frequencies of Salmonella isolation from egg yolk and albumen (4.0% and 3.3%, respectively). Some significant differences between Salmonella isolates were observed in the frequency of recovery from eggs, but not in the frequency or patterns of recovery from reproductive organs. Accordingly, although the ability of these Salmonella isolates to colonize different regions of the reproductive tract in laying hens was reflected in deposition in both yolk and albumen, there was no indication that any specific affinity of individual isolates for particular regions of this tract produced distinctive patterns of deposition in eggs.

The avian coronavirus infectious bronchitis virus (IBV) strain Beaudette is an embryo-adapted virus that has extended species tropism in cell culture. In order to understand the acquired tropism of the Beaudette strain, we compared the S protein sequences of several IBV strains. The Beaudette strain was found to contain a putative heparan sulfate (HS)-binding site, indicating that the Beaudette virus may use HS as a selective receptor. To ascertain the requirements of cell-surface HS for Beaudette infectivity, we assayed for infectivity in the presence of soluble heparin as a competitor and determined infectivity in mutant cell lines with no HS or glycosaminoglycan expression. Our results indicate that HS plays a role as an attachment factor for IBV, working in concert with other factors like sialic acid to mediate virus binding to cells, and may explain in part the extended tropism of IBV Beaudette.

One-day-old, 2-wk-old, and 4-wk-old call ducks (Anas platyrhyncha var. domestica) inoculated intravenously with the H5N1 highly pathogenic avian influenza virus A/chicken/Yamaguchi/7/2004 isolate (Ck/Yama/7/04) were examined clinically, pathologically, and virologically. Clinically, the birds exhibited mild-to-severe neurologic signs and corneal opacity. All birds in the 1-day-old group and one bird in the 4-wk-old group died within 4 days after the virus inoculation. Histologic changes were characterized by severe nonpurulent encephalitis and necrotic lesions of feather epithelium on day 3 postinoculation (PI) or later. Focal necrosis of myocardial cells, pancreatic acinar cells, skeletal myocytes, and corneal epithelial cells was observed. Viral antigens were detected in association with necrotic changes. Viruses were isolated from all examined organs including the skin with many feathers. Serum antibody against the virus was detected in all surviving birds on day 10 PI by hemagglutination-inhibition tests. These results suggest that Ck/Yama/7/04 has a pathogenicity that causes neurologic sign, nonpurulent encephalitis with mortality, and feather lesions for call ducks. Feather lesions with viral antigens and the virus isolation from the skin suggest that Ck/Yama/7/04 has a predilection for feathers in call ducks.

Transmissible viral proventriculitis (TVP) was experimentally reproduced in 2-wk-old specific-pathogen-free chickens and commercial broiler chickens by eyedrop inoculation of adenovirus-like virus (AdLV), isolate R11/3. No clinical signs and no weight gain depression were observed in chickens inoculated with AdLV (R11/3); however, gross and microscopic lesions characteristic of TVP were present in proventriculi of inoculated chickens. Proventriculi of AdLV (R11/3)–inoculated chickens were markedly enlarged, compared with sham-inoculated controls, by day 7 postinoculation (PI). Microscopic lesions in proventriculi of inoculated chickens were detected beginning on day 3 PI and consisted of degeneration and necrosis of glandular epithelium, ductal epithelial hyperplasia, replacement of glandular epithelium with ductal epithelium, and diffuse interstitial lymphoid infiltration; no microscopic lesions were observed in other tissues. AdLV (R11/3) antigens were detected in proventriculi by immunohistochemistry on days 3–10 PI in inoculated SPF chickens and days 3–21 PI in inoculated commercial broiler chickens; no viral antigens were detected in other tissues. AdLV (R11/3) was reisolated from proventriculi of inoculated SPF and commercial broiler chickens on days 5 and 7 PI. No virus, viral antigens, or lesions were detected in proventriculi collected from sham-inoculated chickens. These findings indicate an etiologic role for AdLV (R11/3) in TVP.

Our previous genetic characterization of chicken anemia virus (CAV) in commercial broiler chickens in Alabama revealed a previously undetected polymorphism: a glutamine codon at VP1 position 22, in 7 of the 14 sequences. The novel glutamine codon was always found in association with a VP1 “hypervariable region” identical to CAV field isolates that replicate poorly in culture. The complete genome of CAV73, representative of the sequences with the novel polymorphism, was generated from cloned polymerase chain reaction (PCR) fragments amplified directly from naturally infected tissues. CAV73 had been detected in 31-day-old broilers submitted for examination for reasons unrelated to anemia. After electroporation of the cloned genomes into MDCC-CU147 lymphoblastoid cells, the regenerated CAV caused the culture to fail within 9 days, and the medium contained 5 × 10⁶ TCID₅₀ CAV/ml. Use of MDCC-CU147 cells was essential, as identical electroporation of MDCC-MSB1 cells failed to generate CAV able to destroy the culture within 8 wk. Regenerated CAV73 produced anemia and severe lymphocytic depletion of the thymus when inoculated into susceptible 3-day-old chickens and was reisolated from these chickens. Furthermore, it replicated in low- and high-passage MDCC-MSB1 cells similarly to a low-passage CAV field isolate that contains a different VP1 “hypervariable region.” The regeneration of CAV from PCR products directly from naturally infected carcasses, as performed in this study, provides a tool for the evaluation of distinct genetic polymorphisms that may be detected in specimens where infective virions are no longer available. Our results also provide some insight into the differential susceptibility of cell lines for low-passage CAV field isolates.

Synthetic oligodeoxynucleotides (ODN) containing cytosine-phosphodiester-guanine (CpG) motifs (CpG-ODN) have been shown to be effective immunoprotective agents and vaccine adjuvants in a variety of bacterial, viral, and protozoan diseases in different animal species. The objective of this study was to compare the immune response of chickens to a killed Escherichia coli vaccine combined with oil in water emulsion or with CpG-ODN. Birds were vaccinated with killed E. coli antigens with either 10 or 50 μg of CpG-ODN on days 10 and 20 of age. At day 30, a virulent isolate of homologous E. coli was applied on a scratch site on the caudal abdominal region. Birds were examined for 10 days post-E. coli challenge, and pathologic and bacteriologic assessments were conducted on all birds that were either found dead or euthanized. The E. coli vaccine group that received no CpG-ODN had a survival rate of 65%. In contrast, groups that received the vaccine with CpG-ODN adjuvant had significantly higher survival rate of 92% (P < 0.01) with isolation of low numbers of E. coli from internal organs. Total IgG against E. coli antigens was highest in groups that received CpG-ODN as an adjuvant. Birds that received vaccine containing CpG-ODN had minimal inflammatory reaction without tissue necrosis at the injection site. Severe tissue necrosis was present in birds that received vaccine containing oil in water emulsion adjuvant. This study demonstrated that CpG-ODN is an effective vaccine adjuvant in chickens and results in minimal tissue destruction. This study is the first study in which CpG-ODN has been demonstrated to produce an adaptive immune response, at a significant level, against an extracellular bacterial infection in chickens.

The aims of this study were the identification, cloning, and expression of a genetic region encoding an epitope that induces hemagglutination inhibition (HI) antibody against Avibacterium paragallinarum serovar A and an evaluation of the recombinant protein for immunogenicity in chickens. Although two monoclonal antibodies (MAbs) with HI activity, designated S24-951 and S7-1716-5C, were generated in this study, no reactive proteins with both MAbs were identified by Western blot analysis. A gene fragment of 5157 bp, designated hpa5.1, was cloned from genomic DNA, and a recombinant protein expressed by hpa5.1, designated HPA5.1, reacted with both MAbs on dot-blot analysis. HPA5.1 showed no hemagglutinating activity, but significantly absorbed HI antibodies in the chicken immune serum. Analysis using a series of deletion mutants prepared from hpa5.1 indicated that a 4.8 kbp gene in hpa5.1 is essential for the expression epitope recognized by MAb S24-951. In addition, chickens immunized once with HPA5.1 showed a high protection rate with sufficient HI antibody titers against challenge exposure with a virulent strain of A. paragallinarum serovar A strain 221. These results show that hpa5.1 is responsible for the expression of an epitope that induces HI antibody, and HPA5.1 might be a candidate for the development of a new vaccine against avian infectious coryza caused by A. paragallinarum serovar A.

The genetic organization of the duck circovirus (DuCV) 33753-52 detected in commercial Pekin duck flocks from Long Island, NY, is described. The nucleotide sequence of virus 33753-52 exhibited high similarity with DuCVs previously detected in Germany and Hungary. It is possible that this DuCV from New York shares the same ancestor with the European counterparts. The virus 33753-52 exhibited genetic features characteristic of other circoviruses, such as the presence of two major open reading frames (rep and cap), two intergenic regions, one stem-loop structure, four intergenic direct repeats, and the conserved motifs for the rolling circle replication and for the dNTP binding domain in the Rep protein. This report is the first report of the presence of DuCV in commercial Pekin duck farms in the United States. The clinical and pathologic significance of DuCV in the duck farms located on Long Island needs to be clarified. DuCv was detected in culled birds, due to low body development, leg deformities, or arthritis. Staphylococcus aureus and Riemerella anatipestifer serotype 4 were isolated from some of the DuCV-positive birds. The apparent low prevalence of the virus suggests that at this time, this infection is not a significant problem for the duck industry in New York. However, the immunosuppressive properties of this virus need to be clarified as well as its role as a predisposing agent for other diseases.

In this paper, we report on the evaluation of five influenza antigen detection tests by avian influenza H5N1 virus–positive swab samples to estimate their diagnostic sensitivity. The tests included two chromatographic immunoassays, an H5 avian influenza–specific antigen detection enzyme-linked immunosorbent assay (ELISA), an influenza A antigen detection ELISA, and an H5 rapid immunoblot assay. The results showed that the overall sensitivities of these tests ranged from 36.3% to 51.4% (95% confidence interval ranging from 31.0% to 57.0%), which were comparable to Directigen™ Flu A antigen detection tests but substantially lower than genome detection methods. Diagnostic sensitivity performance is a function of the concentration of antigens in samples and the analytical sensitivity of the individual test. The test sensitivities were significantly higher for sick and dead birds by cloacal, tracheal, or tissue swabs than for fecal swabs from apparently healthy birds, and these tests would not be suitable for surveillance testing of clinically healthy birds. Furthermore, the sensitivity for testing tracheal and cloacal swabs from waterfowl and wild birds was not as good as for chickens. This was most likely to be associated with variation in virus titers between specimens from different bird species. However, the tests showed good sensitivities for testing brain swabs from clinically affected waterfowl species. The results indicate that these antigen detection tests could be used for preliminary investigations of H5N1 outbreaks as a low-cost, simple flock test in sick and dead birds for the rapid detection of H5N1 infection. However, the relatively low sensitivity of the tests as individual bird tests means that they should be used on optimal clinical specimens from diseased birds, testing birds on a flock basis, or testing samples as close to the onset of disease as possible before viral titers diminish. They should be followed up by confirmatory tests, such as reverse transcription polymerase chain reaction or viral culture, wherever possible but could assist in facilitating rapid investigations and control interventions.

During an epidemic of mycoplasmosis in chicken and turkey flocks in North Carolina between 1999 and 2001, isolates of Mycoplasma gallisepticum (MG) from affected flocks were characterized by random amplification of polymorphic DNA (RAPD), and eight distinct RAPD types were identified. MG RAPD type B accounted for more than 90% of the isolates and was associated with moderate-to-severe clinical signs and mortality. The virulence of MG RAPD type B for chickens and turkeys was compared with sham-inoculated negative controls and MG S6 (a virulent strain)-inoculated positive controls. Clinical signs occurred in chickens and turkeys inoculated with either MG RAPD type B or MG S6. However, they were not as frequent or severe as those seen in naturally affected flocks, and there was no mortality in the experimental groups. Based on gross and microscopic findings, MG RAPD type B was equal to or more virulent than MG S6. All MG-inoculated birds were culture and PCR positive at 7 and 14 days postinoculation (PI). Among serological tests, the serum plate agglutination test was positive for the majority of chickens and turkeys (58%–100%) infected with either strain of MG at both 7 and 14 days PI. The hemagglutination inhibition test was negative for all birds at 7 days PI and positive for a few chickens (8%–17%) and several turkey sera (40%–60%) at 14 days PI. Only a single serum was positive by enzyme-linked immunosorbent assay (an MG S6-infected turkey) at 14 days PI.

The objective of this study was to compare Salmonella prevalence and antimicrobial resistance between pasture and conventional poultry farms. We collected the first Salmonella prevalence and antimicrobial resistance data on pasture poultry farms. Fecal droppings were collected from 31 farms from Wisconsin (nine farms from each production type) and the Southeast (North Carolina, Virginia, and South Carolina; five conventional and 10 pasture poultry farms) in a 1-yr period. The specimens were cultured for Salmonella and tested for resistance to 12 antimicrobials. A univariate analysis was conducted to determine the significant differences in prevalence and resistance. At the farm level, no significant difference in Salmonella prevalence was found on 33% pasture and 47% conventional poultry farms (P = 0.4928). On an individual specimen level, flocks reared conventionally had higher prevalence than in pasture (P < 0.0001). Of all the isolates found to have resistance, 80% were from the Southeast. Of all the pasture isolates tested, 5% (8 of 162) were resistant to ceftriaxone, which is higher than previously reported from any production setting. None of the isolates from conventional flocks showed resistance to ceftriaxone. Multidrug resistance (resistance to three or more classes of antimicrobials) was found in 69% of the isolates from conventional farms and 11% on pasture farms in the Southeast (P < 0.0001), with the predominant resistance type of AmCSSuTeAx (ampicillin, chloramphenicol, streptomycin, sulfasoxazole, tetracycline, amoxicillin/clavulanic acid; 62%). About 5% of the pasture isolates from the Southeast showed the AmAxCFCRO (ampicillin, amoxicillin/clavulanic acid, cephalothin, ceftriaxone) multidrug resistance pattern. None of the isolates from Wisconsin were found to be multidrug resistant.

The feasibility of using liver impressions on Flinders Technology Associates (FTA^®) filter paper for the collection, inactivation, and molecular analysis of fowl adenovirus (FAV) was evaluated. FAV I European Union (EU) serotype 1 spotted on FTA^® was shown to be inactivated using specific-pathogen-free (SPF) primary chicken embryo liver cell culture as indicated by absence of cytopathic effect. Sensitivity of the polymerase chain reaction (PCR) test using tenfold dilutions of allantoic fluid from 10⁰ to 10⁻⁴ for the detection of adenovirus serotype 1 on FTA^® cards was determined to be 0.0005 mean tissue culture infectious dose per FTA^® spot. The stability of the DNA from liver impressions on the FTA^® was found to be 198 days when stored at −20°C. In a trial, inclusion body hepatitis (IBH) was experimentally reproduced in SPF chickens inoculated with FAV I EU serogroup 1, 4, 8, or 11, which presented weakness, pallor, depression, dehydration, and mortality within 6 days after inoculation. PCR performed on FTA^® liver impressions from the inoculated birds was able to detect all four viruses, and the nucleotide sequence analysis of the amplified PCR products (1219 bp of the hexone gene) revealed the expected serotypes. In addition to the trial, 55 clinical samples were analyzed from liver impressions on FTA^® cards, and FAV was detected in 11 of 55 (20%). Sequencing analysis showed that the viruses were EU serotypes 4, 5, 9, and 10. The results demonstrate that FTA^® filter paper inactivates the FAV I and maintains the DNA template for molecular analysis.

A precocious line of Eimeria meleagridis was developed by repeated propagation of the parasite in young turkeys and collection of the very first oocysts produced following infection. After 20 generations of selection, the prepatent period was reduced by 4–8 hr. Weight gain of poults given this line, from days 0–3 after infection, was significantly greater than that of poults given the parental strain, indicating that selection resulted in a loss of pathogenicity. Poults immunized with the precocious line produced no oocysts following challenge with the parental strain, indicating that immunogenicity was retained following selection. This is the first published report of the selection of a precocious line of Eimeria in the turkey.

Crows have been the centerpiece of avian West Nile virus (WNV) surveillance and research in North America. This work has demonstrated variation in susceptibility to WNV infection between American (Corvus brachyrhynchos) and Fish Crows (Corvus ossifragus). The higher WNV-associated mortality rate in American Crows compared with Fish Crows suggests that WNV antibody prevalence would be greater in the Fish Crow population. The objectives of this study were to 1) determine whether Fish Crows had higher WNV antibody prevalence than American Crows, 2) determine the persistence of antibodies to WNV in naturally infected Fish Crows, and 3) develop a technique to distinguish Fish Crows from American Crows on the basis of sequence analysis and restriction enzyme digestion of a mitochondrial DNA fragment. West Nile virus antibody prevalence was 16.5% (n = 97) in Fish Crows and 5.7% in American Crows (n = 53) collected from Georgia between 2004 and 2006. Antibodies persisted at high titers for 12 mo in Fish Crows. This is the first report of WNV antibody persistence in a crow species. A polymerase chain reaction technique paired with restriction enzyme digestion easily distinguished American Crows from Fish Crows on the basis of a mitochondrial DNA fragment.

Typically highly pathogenic avian influenza (HPAI) viruses spread very rapidly among chickens within sheds. However, the spread was slower than expected for the initial 10 days of the index farm in Japan during 2004. This slow spread, as well as the lack of gross lesions, clinical signs, or high mortality, hindered the field veterinarian from reporting a suspected HPAI outbreak to the veterinary office. To understand the field conditions for the slow virus spread, we examined contact and airborne transmission of the H5N1 virus to chickens in a negative-pressure isolator using various numbers of infected chickens and separate compartments. We found that the contact transmission did occur inefficiently when one or two chickens were infected, whereas the transmission was efficient when four chickens were infected. Airborne transmission of the HPAI virus was also dependent on the number of infected chickens and was less efficient than contact transmission. These data together with field observations suggested that number of infected chickens, chicken house types, and amount of environmental contamination might affect the virus transmission efficiency to chickens.

A 15-cm segment of small intestine from a 7-wk-old broiler chicken presented for slaughter was encased by a firm, white mass. Other tissues were grossly unremarkable. Microscopically, the enteric serosa and peripheral muscularis of this segment of small intestine were replaced by a fibrosarcoma. Numerous linear, intracytoplasmic, eosinophilic inclusion bodies were present in smooth muscle cells of the muscularis of the small intestine, and a few similar inclusions were present in the muscularis of the proventriculus. In the heart, there were rare intracytoplasmic inclusions typical of viral matrix inclusions. Ultrastructurally, inclusion bodies in enteric smooth muscle were viral matrix inclusions, and virions resembling avian retroviruses were present in adjacent intercellular spaces. Polymerase chain reaction (PCR) of the deoxyribonucleic acid (DNA) extracted from tumor tissues indicated the presence of proviral DNA of subgroup J avian leukosis virus. This is the first description of the light microscopic appearance of these viral matrix inclusions in enteric smooth muscle.

We report the prevalent status of avian paramyxovirus serotype 2 (APMV-2) in China. Between 2003 and 2005, 9156 sera in total were collected and screened for APMV-2 antibodies by using the hemagglutination inhibition assay. The averaged seropositivity of APMV-2 for chickens, ducks, peacocks, ostriches, and partridges was 42.9%, 25.1%, 45.8%, 47.6%, and 80.0%, respectively. The results of this survey indicate that the distribution of APMV-2 is very widespread in China and that more attention should be paid to the influence of APMV-2 on poultry production.

West Nile Virus (WNV) infection manifests itself clinically and pathologically differently in various species of birds. The clinicopathologic findings and WNV antigen tissue distribution of six great gray owls (Strix nebulosa) and two barred owls (Strix varia) with WNV infection are described in this report. Great gray owls usually live in northern Canada, whereas the phylogenetically related barred owls are native to the midwestern and eastern United States and southern Canada. Naturally acquired WNV infection caused death essentially without previous signs of disease in the six great gray owls during a mortality event. Lesions of WNV infection were dominated by hepatic and splenic necrosis, with evidence of disseminated intravascular coagulation in the great gray owls. WNV antigen was widely distributed in the organs of the great gray owls and appeared to target endothelial cells, macrophages, and hepatocytes. The barred owls represented two sporadic cases. They had neurologic disease with mental dullness that led to euthanasia. These birds had mild to moderate lymphoplasmacytic encephalitis with glial nodules and lymphoplasmacytic pectenitis. WNV antigen was sparse in barred owls and only present in a few brain neurons and renal tubular epithelial cells. The cause of the different manifestations of WNV disease in these fairly closely related owl species is uncertain.

A 6-mo-old female scarlet macaw (Ara macao) was presented after a 2-mo period of anorexia and weakness. The bird was reluctant to fly 1 wk before referral due to a painful left wing. Physical examination revealed a firm swelling around the left shoulder. On radiographs, the diaphysis and proximal metaphysis of the left scapula were radiolucent. Computer tomography revealed an osteolytic process, suggestive of a bone tumor, affecting the left scapula. Cytology of a fine needle aspiration biopsy of the mass showed erythrocytes, a proliferation of spindle-shaped mesenchymal cells, and multinucleated giant cells (osteoclasts) suggestive of a giant cell tumor. The left wing, including the scapula, was amputated. The bird showed a fast recovery but died 1 hr later. Findings during the pathological examination were compatible with shock due to blood loss. The shoulder process was characterized as a giant cell tumor. To our knowledge, this is the first complete report of a giant cell tumor of the bone in a bird.

A 30-yr-old blue-fronted Amazon parrot (Amazon aestiva aestiva) was presented to the clinic with a history of sneezing more often during the last 2 mo. Physical examination revealed only a mild nasal discharge. Complete hematologic and plasma biochemical examination showed no abnormalities. Computerized tomography (CT) of the complete bird showed generalized lung alterations consistent with lung fibrosis. Two lung biopsies were taken. The results of the histologic examination of the biopsies confirmed the tentative CT diagnosis of pulmonary interstitial fibrosis. To our knowledge this is the first reported case of chronic pulmonary interstitial fibrosis diagnosed by means of a lung biopsy in an avian species. The histologic characteristics are discussed and compared with those of human idiopathic pulmonary fibrosis.